Cushioning device



Oct. 18, 1932.

D. F. SPROUL CUSHIONING DEVICE Filed Oct. 30, 1929 2 Sheets-Sheet 2 Patented Oct. 18, 1932 UNITED STATES PATENT OFFICE DONALD F. SPROUL, OF CHICAGO, ILLINOIS, ASSIGNOR '10 C.A'.R.I)WII.1I..Lv WESTINGHOUSE COMPANY, A CORPORATION OF DELAWARE- CUSHIONING DEVICE Application filed October 30, 1929. Serial No. 403,423.

The invention relates to the friction spring type of cushioning device in which there is employed a helical-spring formed of av rod of square section, or at least flattened on that may take, the spring constitutes the outer casing which encloses the other elements of the gear, and segmental tapering friction shoes engage the inner face of the spring, cooperating with a p'air of segmental wedging shoes which in turn are in wedging engagement with a central thrust member.

In the drawings:

Fig. 1 is a detail central vertical longitudinal section through the underframing of a car showing the improved gear applied thereto;

v Fig. 2 is a view on the line 22 of Fig 1;

Fig. 3 is a centrallongitudinal plan sec tion of the gear, the associated followers being shown in detail;

Fig. 4 is an end view of the gear;

Fig. 5 is a sectional view on the'line 55 of Fig. 3;

Figs.- 6 to 9 are views in perspective of various elements of the gear; and

Fig. 10 is a detail sectional view of a pair of cooperating wedges employed in the gear. I

A pair of center or draft sills of a railway car are shown at 15, 15, and, as usual, carry draft and buffing lugs 16, 17 with which cooperate a pair of followers 18, 19. The gear is enclosed within a yoke 20 of usual construction, and comprises a helical spring 21, which is shown as formed of a rod rolled to square section so that the inner face of the spring may present a cylindrical surface. This spring encloses as an outer casin the remaining elements of the gear, and has arlower, as 19, only. 4

A central thrust member 22 seats against the follower 18, opposite to the one engaged by the spring, and extends along the axis of the gear, its length being such that-upon full. compression it serves as a limiting stop. The

ing, through a spring seat, upon one folelement 22 is provided with two pairs of forwardly facing and inwardly inclined wedges 23, 24, which cooperate with complementary wedges 25, 26, formed on the inner faces of a pair of segmental friction shoes 27 the rear ends of which are outwardly flanged, as

shown at 28, to engage over a spring seat 29. At least one of the cooperating wedge faces,

as 23, is" grooved in the direction of travel,

insuring frictional contact and providing for the free dischargefrom between the wedges of the abraded material.

When, as in the device as illustrated, two

sets of wedging surfaces are arranged in tan-' dem the grooving of these faces has the additional advantage-that it quickly provides for uniformity of contact of the two sets of wedges in the event that in the manufacture the wedge faces on each -or either element are somewhat out of parallel or otherwise distorted. In'the manufacture of devices of this character it is. impracticable to resort to machining, and the cast elements 'are,

therefore, put into service as they come from the mold and are consequently rough and I may be somewhat distorted. Where there are two sets of wedging surfaceson a single element, as in the present instance, any such distortion causes unequal action, all or the major portion ofthe load being borne by one of them, causing undue wear thereof. By making the surface other than strictly fiat, as by grooving, such wear is accentuated and furthermore, the metal will be caused to flow into the depressions, thereby speedily bringing the companion wedge into service.

As soon as the set of wedges which have been thus in engagement are worn to conform to-the other set of wedges, all of the.

wedgesare subjected to the same pressure and wear uniformly.

Inter-posed between eachof the friction shoes 27 and the inner face of the spring 2laec is a tapering segmental friction shoe 30, the outer end of which is provided with an outstanding lateral flange 31, taking over a spring seat 32 at the end of the gear which engages the follower 19. A bolt 33, setting axially through the thrust element 22 and into a retaining element 34, which engages the seat 32, binds the elements of the gear together for convenience in shipment and installation. \Vhile the elements 32 and 34 are shown as separate castings, they may obviously be formed as a single element. 7

In assembling the device the spring is seated against the follower 32; the elements 22 and 27 are assembled and inserted within the spring, which is then compressed without bringing the wedges into action, and

the elements 30 are inserted through the openings in the follower 32, and the bolt 33 is now applied. The spring being relieved the parts assume the relative positions as shown in Fig. 3. p

In buff, the follower 18 is forced inwardly by the draw-bar, .wedging the shoes 28 laterally outward against the tapering shoes 30, and also carryin g them forward, causing the compression of the spring and developing friction between the coils of the spring and the shoes 30, and between the latter shoes and the shoes 27. The tapering form of the shoes 30 greatly augments the radial pressure, causing the wedge faces of the shoes 27 to creep of the thrust element, thereby still further compressing the spring. Prompt release is insured by the expansive force of the spring, but is sufficiently retarded by the friction of the parts.

In draft, the follower 19 is moved forwith it the spring seat 32 shoes 30. The pressure of the spring upon the flanges 28 of the shoes 27 urge the latter forwardly, thus setting up a wedging action between these shoes and the thrust member and limiting the longitudiifal movement of the shoes. The advance wardly, carrying and the tapering of the tapering shoes increases the wedging action and the compression of the spring. The wedge faces 23, 24, are shown as grooved longitudinally, thereby securing increased durability by providing for a displacement of the metal under severe pressure and thus lessening the tendency to wear.

In practice, the elements 27 will be case hardened, the element 22 being of softer material. In service, the wedge faces as 24, 26 may not bear upon each other uniformly throughout their entire areas, because of misplacing or distortion of thedraft lugs, or other parts of the structure and excessive pressure upon one portion of the softer wedge, as 24, will cause the metal to flow into the grooves, thereby changing the angle the wedge face transversely and bringing its enforwardly on the wedging faces tire face into bearing upon the cooperating wedge.-

A plurality of sets of wedges are advisable in a draft gear because of its length in order to distribute and equalize the lateral pressure. In devices, such as bolster supports and the like, where the overall length is comparatively short, a single set of wedges will serve.

I claim as my invention- 1. In a cushioning device, in combination, a follower, a thrust element opposed to the follower and having spreading wedge surfaces, a tie-rod connecting the follower and thrust element, segmental friction shoes cooperating with the wedge surfaces of the thrust element and having radially projecting flanges at their rearward ends, a helical spring reacting between the shoe flanges and the follower, and friction shoes interposed between the first-named shoes and the spring, the follower being apertured for the insertion of the second-named shoes and suchshoes having radially extending flanges at their outer ends engageable with the outer face of the follower.

2. In a cushioning device, in combination, a follower, a thrust element opposed to the follower and having spreading wedge surfaces, segmental friction shoes cooperating with the wedge surfaces of the thrust element and having radially projecting flanges at their rearward ends, a helical spring reacting between the shoe flanges and the follower, and friction shoes interposed between the first-named shoes and the spring, the follower being apertured for the insertion of the second-named shoes and such shoes having radially extending flanges at their outer ends engageable with the outer face of the follower.

In testimony whereof I aflix my signature.

DONALD F. SPROUL. 

